Preparation

• Step 1
  Peel cucumber; set peel aside. Cut flesh into 1" pieces and transfer to a blender.
  Step 2
  Heat sugar, ginger, chile, star anise, cloves, reserved cucumber peel, and 1 cup water in small saucepan over medium, stirring occasionally, until sugar is dissolved. Remove from heat, cover, and let sit 10 minutes.
  Step 3
  Strain syrup through a fine-mesh sieve into blender; discard solids. Add lemon juice and 2 cups ice and blend until smooth. Strain agua fresca through sieve into a medium pitcher; discard solids.
  Step 4
  Pour agua fresca into ice-filled glasses and garnish with cucumber ribbons.
  Do ahead: Agua fresca can be made 2 days ahead. Cover and chill. Stir well before using.